Usability of portable communicators, particularly cell phones, is greatly enhanced when size is reduced. Smaller packaged cell phones may be conveniently stored by a user in purses, briefcases, and more recently, even in shirt pockets.
One impediment to reducing the size of a cell phone is the antenna. Cell phone antennas need to extend to a length to sufficiently avoid interference with the human operator. The blocking effect of a human head can adversely affect the low power signal between a base station and a cell phone, thereby reducing the quality of communications. Since a cell phone antenna should retract into the cell phone housing for protection when not in use, the length of typical elongated conductor antennas used in cell phones must not exceed the overall housing length.
Presently, some of the smallest commercially available cell phones use a thin elongated flexible conductor. Two separate contacts are disposed on a printed circuit board within the phone to electrically contact a contact at the end of the antenna in separate retracted and extended positions. This simple elongated flexible conductor design is for protection and longevity. When extended outside of the housing, cell phone antennas are frequently subjected to forces which would permanently deform or break rigid conductors. For this reason, the retractable antenna designs used in other applications, such as automobile radio antennas, are avoided in cell phones and similar portable communicators.
In sum, cell phone antennas should be flexible, should retract for protection during times of nonuse, and should provide a sufficient length when extended to maximize signal quality by avoiding user interference, while also permitting the cell phone housing which accepts the antenna in its retracted state to be as small as possible. In addition to these specific desirable qualities, the performance of the antenna should be robust and should not significantly degrade from a small number of cycles of retraction and extension during use.
Size and operational improvements would result from an improved antenna which has an extended length exceeding that of its retracted length, maintains electrical contact in separate retracted and extended positions, and withstands operational cycling. There is therefore a need for an improved cell phone antenna which exhibits such qualities.